Chemical treatments on human hair such as relaxers, straighteners, waves, perms, oxidative and direct dyes, highlights, lightening compositions and bleaches are much sought after by consumers. Such chemical treatments employ various reducing and oxidizing agents, alkalizing agents, and coloring agents that help re-shape, artificially color, decolorize, modify the color shade/tone or enhance the appearance and color of hair.
However, such chemical treatments and the various ingredients employed in these treatments are generally known to result in hair breakage and loss, dryness, roughness and brittleness, and skin and/or scalp irritation. Often times, these chemical treatments are used with the application of heat and mechanical combing or brushing which may cause more damage to the hair.
One example of a chemical treatment that may adversely affect the quality of hair fibers are conventional permanent hair dyeing products which use the combination of compositions containing oxidative dye precursors, also known as primary intermediates or oxidation bases, and oxidizing products containing oxidizing agents such as hydrogen peroxide. Hair dyeing compositions typically contain aqueous ammonia as an alkalizing agent and for activating the oxidizing agent. These alkalizing agents also cause the hair shaft to swell, thus allowing the small oxidative dye molecules to penetrate the cuticle and cortex before the oxidation condensation process is completed. The resulting larger-sized colored complexes from the oxidative reaction are then trapped inside the hair fiber, thereby permanently altering the color of the hair. However, the use of ammonia may affect the user, not only because of the undesirable odor of ammonia, but because it may also pose greater risks of intolerance, for instance, irritation of the scalp and stinging.
Chemical treatments products for shaping or changing the shape and configuration of hair include hair straightening or relaxing products which are generally composed of a strong hydroxide base compound, typically, an alkaline metal hydroxide, that breaks the bonds in the hair in order to straighten or relax curly/kinky hair. These products are usually applied quickly and can only remain in the hair for a very limited amount of time because the alkalinity of such products, if not rinsed from the hair at the appropriate time, can damage the hair, as well as cause chemical burns to the scalp and areas surrounding the hair.
Other straightening or relaxing formulations use guanidinium hydroxide which can be formed from the reaction of guanidine carbonate and a soluble hydroxide such as calcium hydroxide. While such a system may provide a better relaxing efficacy and better skin tolerance, the reaction also forms calcium carbonate which makes the final rinsing of the hair much more difficult, and leaves on the hair and the scalp, mineral particles that give the hair a coarse feel and an unattractive appearance resembling dandruff.
Hair straighteners or reshaping technology can also employ reducing agents such as thighlycolic acid and cysteine compounds or non-thiol-based reducing agents such as sulfites and bisulfites which permanently reduce hair bonds or protein denaturants in combination with heat.
Other straightening products contain formalin or formalin derivatives, which are known to break down to formaldehyde with high heat, such as during flat ironing of the hair. One major drawback is the generation of formaldehyde fumes which have been found to cause headaches, respiratory, eye, and mucous membrane irritations, respiratory illnesses, cancer, or even death.
Thus, in view of the potential irritation to the skin or scalp, and the potential damage to hair caused by available chemical treatments, successive chemical treatments of the hair within a short period of time, i.e., a few hours, is generally not recommended. More particularly, conventional and customary practice by consumers and hair dressers is to have a waiting period of at least 24 hours, preferably, a few days, in between two or more different chemical hair treatments. Such practices may also help minimize other types of problems which may arise from successively chemically treating the hair as a result of undesired reactions between successive different chemical treatments.
An example of a hair treatment process that may result in the problems described above may consist of a hair straightening or relaxing process that is immediately followed by a conventional oxidative hair color that employs hydrogen peroxide. Such a process can result in a significant decrease in the quality of the hair fibers, leading to increased roughness and damage to the hair and/or prevent the hair's color or shade from being lightened, bleached, dyed or altered correctly after the chemical treatment.
Successive chemical treatments of the hair can also be inconvenient to the consumer who has to spend a lot of time going through two different treatments, wait in between treatments and return to the hair dresser for the second treatment.
Thus, there exists a need to improve existing methods, compositions and hair treatment regimens or systems that allow the consumer to effectively change the appearance, that is, the color and/or shape of their hair in a convenient, efficient and safe manner, while minimizing the damage to the hair and other adverse effects and disadvantages to the consumer. There is also a need for processes and/or compositions which can take the place of successive chemical treatments.
For example, it would be desirable to oxidatively dye hair and chemically shape or straighten the hair at the same time. However, this may require introducing other ingredients into hair coloring compositions which may affect the suspension and/or solubility of the dye compounds in the dye composition, the hair-lightening properties of the dye composition, the rheology or viscosity of the dye composition, and the dye application properties. Thus, the selection of ingredients presents an even greater challenge to the manufacturers of hair treatment products because the composition/process not only has to remain effective, it also has to remain safe to use and not cause more irritation to the skin and scalp.
Thus, there is still an ongoing need and desire to provide a composition and process for effectively coloring and/or lightening the color of hair such as achieving chromaticity of the color and homogeneity of the coloration along the hair fiber in a manner that is efficient, yet safe and minimizes damage to the hair fiber. At the same time, it is highly desirable that these composition and process are able to impart other cosmetic and functional benefits to the hair such as curl and frizz reduction, greater and longer lasting curl pattern, increased manageability of hair and fiber strength and less hair treatment or processing times to achieve these attributes.